Fresh deployment of Exchange 2013.  As you try to connect to the management console https://localhost/ecp/ with a valid administrator account, it redirects to OWA and responds with “:-( Something Went Wrong, A problem occurred when trying to use your mailbox.”

This seems to be related to left over Exchange attributes in Active Directory.  I tried everything from a multitude of TechNet articles including the following:

1. Rebuilding the ECP front end and back end (Reference)
2. Adding appropriate permissions to the administrator account
3. Connecting directly to the back end by using port 444
4. Messing with certificates (Reference)
5. Many articles mentioned having CAS and MBX roles installed, but these were installed on the same machine at the same time
6. Manually creating the administrator mailbox using the exchange shell

Finally I tried just creating another user account in AD and gave it permissions to manage Exchange by adding it to the group ADUC–>Domain.local–>Microsoft Exchange Security Groups–>Organization Management.

That allowed access to the ECP and after some more digging in ADSIedit, I can see old exchange attributes attached to the enterprise Administrator account.  I believe this is the problem as the management console lists Administrator as already having a “legacy” mailbox.  The attributes are referencing exchange servers that no longer exist in the environment.

I plan to start ripping out old exchange attributes to test this theory.